1. Field of the Invention
The present application is related to a method of quantitatively evaluating a golf club.
2. Description of the Related Art
Generally, a golf player evaluates a golf club according to his/her sense (feeling). The evaluation of the golf club by the golf player is done in the form of questionnaire, for example. Based on the evaluation, it is judged if the golf player likes or dislikes the golf club. It is expected that the evaluation includes various factors such as: “easy to hit the golf ball”, “easy to swing the golf club”, “sense of hitting the golf ball” or the like. Such evaluation is done subjectively.
Senses of a human tend to vary depending on his/her physical condition, surroundings and so on. Hence, the result of the evaluation described above tends to vary depending on the physical condition of a testee, the surroundings of a test site and so on. Besides, the above evaluation is done in a qualitative manner only.
In these connection, JP 2007-130088 A (or US 2007/0105641 A1 or US 2008/0234065 A1 corresponding thereto) discloses a golf club having a relatively small primary moment and a relatively large secondary moment. In the embodiment therein, sensuous evaluation is done if a golfer feels easy to swing the golf club.
JP 3735208 B discloses an invention having an object of providing a golf club which is easy to swing in order to allow a golf player to keep a stable swinging motion. According to this prior invention, the golf club has a predetermined range with respect each to: an moment of inertia around a end of a grip (grip end); a length of a golf club; and a frequency of bending vibration of the golf club.
JP 2000-202070 A discloses an invention which may cope with difficulty of swinging an elongated (long) golf club. In this prior invention, a length of the golf club, a weight of the golf club, a moment of inertia of the golf club and so on are defined each in a predetermined range.